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ATOM™ incremental encoder system with RKLF linear and partial arc scale


  • Readhead size: 20.5 x 12.7 x 8.35 mm (20.5 x 12.7 x 7.3 mm for FPC version)
  • Resolutions down to 1 nm
  • Speed up to 20 m/s
  • Analogue or digital outputs
  • Low Sub-Divisional Error (SDE) of < ±75 nm for 20 µm version and < ±120 nm for 40 µm version


  • Miniature package
  • Filtering optics design enabling high dirt immunity
  • Diagnostic kit to assist challenging installations and aid system optimisation
  • Narrow 6 mm wide scale suitable for space limited applications
  • Suitable for partial arc measurement
  • Assured quality

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What is ATOM?

ATOM is Renishaw's miniature non-contact optical incremental linear and rotary encoder system. Its innovative design combines miniaturisation with leading-edge signal stability, dirt immunity and reliability. This combination is unique in the market place and represents a significant advance in the performance and reliability of miniature encoders.

ATOM is supplied in hi-flex cable and flexible-printed circuit (FPC) variants with either 20 µm or 40 µm scale options.

A range of interfaces is available including the standard Ri, a high-performance Ti and the compact open ACi interface.

What is RKLF scale?

RKLF is a narrow, low profile stainless steel tape scale featuring 20 µm and 40 µm pitch incremental graduations and customer selectable reference marks. It is accurate to ±5 µm/m and available in lengths up to 10 metres (> 10 m on request). The RKLF is mastered to the machine substrate giving improved metrological performance when the scale ends are rigidly fixed to the substrate.

The flexible RKLF40 scale is also suitable for partial arc measurement where the small cross-sectional area allows it to be wrapped around a drum, shaft or arc with a minimum radius of 26 mm.

Why choose this encoder system?

Miniature encoder where space is at a premium

ATOM, available in sizes as small as 7.3 mm x 20.5 mm x 12.7 mm, allows for integration in the tightest of spaces. There are a number of options to choose from including both cabled and component FPC versions.

High reliability and system performance

ATOM is the world's first miniature encoder system incorporating Renishaw's unique filtering optics design. This is further enhanced by dynamic signal processing within the readhead including Auto Gain Control and Auto Offset Control. This combination allows ATOM to have higher dirt immunity and signal purity which is comparable to, if not better, than our standard size readheads with SDE's as low as ±75 nm on 20 µm readheads and ±120 nm on 40 µm readheads. The result is smoother velocity control for improved scanning performance and increased positional stability, essential parameters for many motion control applications.

Narrow, robust and versatile scale

RKLF is a robust, 6 mm wide stainless steel encoder tape scale with a thickness of 0.15 mm. This allows the scale, when rigidly fixed to a machine axis, to become ‘mastered' to the machine substrate, matching its thermal expansion coefficient and behaviour. Differential movement between the scale and the machine is thus minimised.

RKLF partial arc encoder scales

RKLF40 encoder scales can be conveniently cut to required length and mounted on a simple cylindrical substrate with no requirement for complex mounting features or tightly toleranced alignment surfaces.

Interface options

ATOM comes with a variety of interface options which allows greater flexibility to integrate the encoder within your system design.

Ri interface

  • Ri interfaces offer analogue 1 Vpp or digital interpolation outputs down to 50 nm (clocked) and 0.5 μm (non-clocked) in a compact low cost package.
  • This is contained within an industry standard 15 way D-type connector shell, including CAL button.
Ri interface (square)

Ti interface

  • Ti interfaces are designed for applications that require higher speed, lower SDE and digital interpolation down to 1nm and include a CAL button.
  • Clocked outputs have been optimised for speed and performance at all resolutions for industry-standard controllers.
  • Analogue variants are also available.Ti interface (square)

ACi interface

  • ACi interfaces are a range of high performance, miniature, open interpolator subsystems.
  • They bring unparalleled price-performance benefits to today's motion systems that need fine resolution coupled to high speed performance in an ultra compact, open format, small footprint solution and have provision for calibrating the system.
  • Digital interpolation down to 10 nm at up to 40 MHz clocked output is available.
  • FPC, cabled or PCB connector versions available.
Website: ACi for ATOM readhead

Optional diagnostic kit

ATOM™ diagnostic kit (software and hardware)

ATOM diagnostic software can be used to optimise the installation of ATOM encoders and provide a quick and comprehensive system calibration. The software must be used in conjunction with the ATOM diagnostic hardware which can be purchased from Renishaw using part number A-9411-0011. The hardware is connected to the PC via the USB cable (provided in the kit) or in-line with the customers' electronics.

Find out all about the ATOM diagnostic kit.

Technical specifications

Measuring standard

Narrow stainless steel tape scale with self-adhesive backing tape, for mounting directly to a substrate

Suitable for partial arc applications (minimum radius for partial arc: 26 mm)

Readhead size (LxWxH)

Cable variant: 20.5 mm x 12.7 mm x 8.35 mm

FPC variant: 20.5 mm x 12.7 mm x 7.3 mm

Scale pitch

20 μm* and 40 µm

*20 μm not suitable for partial arc applications

Coefficient of thermal expansion at 20 °C

Linear: matched to substrate material when scale ends are fitted with end clamps
Partial arc: 10.1 ±0.2 μm/m/°C

Accuracy grade at 20 °C

40 μm (high accuracy): ±5 μm/m

40 μm: ±15 μm/m

20 μm: ±5 μm/m

Reference mark

Optical de-selectable

Limit switches


Scale length

Up to 10 m (> 10 m on request)

Maximum speed


(see data sheet for details)

40 µm: up to 20 m/s

20 µm: up to 10 m/s

Dependent on interface type, see data sheet for details

40 µm: up to 20 m/s

20 µm: up to 10 m/s

Sub-Divisional Error (SDE)

40 µm version: Typically < ±120 nm

20 µm version: Typically < ±75 nm

Dynamic signal control

Real time signal conditioning including Auto Gain Control (AGC) and Auto Offset Control (AOC) for optimised performance across a range of operating conditions

Incremental signals

1 Vpp
Resolutions from 10 µm to 1 nm

Electrical connection

Cable readhead: Interboard connector compatible with the Ri, Ti and ACi interfaces or 15 way, D-type connector
FPC readhead: 16 core, 0.5 mm pitch, compatible with ACi

Power supply

5 V ± 10% < 50 mA (readhead), < 200 mA (with Ti interface), < 100 mA (with Ri interface), < 100 mA (with ACi interface) (unterminated)

Vibration (operating)

100 m/s² max @ 55 Hz to 2000 Hz

Shock (non-operating)

1 000 m/s², 6 ms, ½ sine

Operating temperature

0 °C to +70 °C


Cable variant: IP40
FPC variant: IP20 (with lid fitted)

Ri/Ti interface: IP20

ACi interface: IP00

Refer to data sheets for full details.